OSCII Activity A.6

Restoring yield productivity and C sequestration in organic farming systems on the Prairies: The role of composted manure in long-term studies

Activity summary

This research seeks to better understand how nutrient depleted organically-managed soils can be restored. Past research at the Glenlea site gives strong clues about solutions. One answer lies in recycling animal wastes in the form of composted manure back to the land.

This research will be conducted on two long-term organically farmed sites. The first is the Glenlea rotation, Canada’s oldest organic field crop experiment. Some highly productive systems at Glenlea have “run out” of easily available nutrients, making this an ideal site to conduct soil nutrient restoration research. The second site is an organic farm in southeastern Saskatchewan, where organic practices have been used for 25 years. The soils at this site are not yet seriously depleted, but levels of soil phosphorous are low.

This four year study will test different compost formulations and different application frequencies. The study will also measure how quickly soil nutrients are replenished using this system of animal waste recycling. These are practical considerations for farmers.

How organic farming practices affect the soil's ability to sequester carbon is a question of significant interest to society. When nutrients become depleted in organic systems, soil carbon sequestration declines – we have observed these phenomena at Glenlea. Therefore, an important question here is how will restoring the nutrient status of soil restore the soil’s ability to absorb and hold carbon.

Not only will this research provide important scientific information, it is also very visual. Nutrient deficiencies are often very easy to detect in field crops. On the flip side, corrections to nutrient problems are also easy to visualize, making this project useful as a field teaching tool.